1. Technical Field of the Invention
The present invention relates to item conveyors of the roller or belt type which may be installed on a ceiling or floor or built into a shelf facility. The present invention further relates to such conveyors manufactured substantially, if not entirely, of molded, non-metallic constituent parts.
2. Description of Related Art
The configuration of roller or belt type conveyors is well know to those skilled in the art. It is also well known to manufacture such conveyors substantially entirely from metallic (primarily aluminum, steel, stainless-steel or some other structural metal) constituent parts. Examples of such constituent parts include side frames, brackets, rollers, supports, hangers, stands, nuts, bolts, slider bed sections, and the like. A number of difficulties are encountered with the use of metallic part-based conveyors. One noted difficulty concerns noise. Metallic conveyers are well known to rattle, and in a large facility with several hundred linear meters of conveyors, the cumulative rattling noise from these conveyors can be quite disturbing. In fact, occupational health and safety guidelines for the workplace may dictate maximum acceptable workplace noise levels which can be violated by such conveyors. Another difficulty with metallic conveyors concerns maintenance. Metallic conveyors generally must be periodically re-painted. If regular painting maintenance is ignored, the conveyors may become unsightly due to scratching, flaking, peeling or fading and further become more susceptible to wear, decay and rust. Maintenance issues also appear in the context of addressing noise (rattling) through manual repair activities and replacing degraded components. Other maintenance issues concern corrosion of metal parts. Yet another difficulty with metallic conveyors revolves around cost issues. Fabricating metallic conveyors can be quite expensive, not only from the perspective of original design, manufacture and installation, but also with respect to upkeep, repair and maintenance. One further difficulty with metallic conveyors is that they are ill-suited for installation in electromagnetic, electrostatic or radio frequency sensitive environments. For example, the danger of static discharge injuring an employee or maintenance person is a significant concern, and additional protective measures must be taken to ensure proper grounding of the conveyor apparatus. As another example, conveyors are now needed for use in conveying items marked with radio frequency (RF) identification tags, and the metallic nature of the conveyor components adversely affects the ability of an RF reader to accurately detect those tags. What is needed therefore is a new roller or belt conveyor design that addresses the foregoing difficulties.
A conveyor assembly includes a frame and a transport means for conveying articles that is supported by the frame. The frame is manufactured from a non-metallic material possessing physical characteristics that are substantially similar to those experienced with structural metals. The transport means may comprise either a plurality of transport rollers or a belt.
More specifically, in a preferred embodiment, the non-metallic material used for the frame is an elastomeric material. This elastomeric material may comprise an engineering thermoplastic (like polyurethane) blended or combined with at least one of an ultra-high molecular weight polyethylene, a rubber and/or other filler materials to change the physical properties of the material in a manner similar to alloying steel. A preferred blend features a combination of polyurethane and flourinated polyethylene into curable an elastomeric composite engineered to have mechanical properties including modulus and strength properties which approach those of structural metals and metal alloys.
A conveying system in accordance with the present invention includes the conveyor assembly as described above in combination with an RF reader device wherein the RF reader device is position to read RF tags applied to items conveyed past the reader by the conveyor assembly.
The present invention further includes individual conveyor structural parts and components manufactured of a non-metallic material possessing physical characteristics that are substantially similar to those experienced with structural metals. These structural parts and components comprise: conveyor side frames, lower frames, and slider beds.